Modal testing of bridges using low-weight pneumatic artificial muscle actuators

The identification of the modal parameters of bridges and other large civil constructions has become an important research issue. Different approaches have been proposed depending on the excitation used: ambient excitations (OMA), artificial excitations (EMA), or a combination of both (OMAX). In practice, it turns out that not all modes are well excited by the ambient forces, and so, the application of an artificial actuator is advisable. The problem is that larger constructions often require large and heavy excitation devices, which are not very easy to manipulate. In this paper, the possibility to use light-weight pneumatic artificial muscles (PAM) is investigated. The characteristics of the used PAM are described and the application of this PAM in modal testing is introduced. Both a laboratory setup and a setup on a bridge for pedestrians is discussed.